X(468), X(523), X(5000), X(5001)
Ωa, Ωb, Ωc : centers of the Apollonius circles
K608 is a central non-pivotal cubic with center X(468) and pole the barycentric product Ω of X(468) and X(523), a point on the orthic axis.
It has three concurring asymptotes : one of them is the orthic axis and the two other are parallel at X(468) to those of the rectangular circum-hyperbola that contains X(468) whose perspector is Ω.
K608 is the locus of point M such that M and its Ω-isoconjugate M* are conjugated with respect to any circle of the pencil generated by the circumcircle, the nine point circle NPC, the orthoptic circle of the Steiner inscribed ellipse SOC, etc.
K608 contains P1, P2 which are the antiorthocorrespondents X(5000), X(5001) of the Lemoine point K. See Table 55.